homemade dehydrator problems

[rhoda_bruce]

DH recycled a junk refrigerator into a dehydrator, by gutting it a bit and making a few ventilation holes in the top, freezer section and then simply putting a light fixture and 100 watt bulb as a heat source.
We tried it out yesterday pm and he informs me of moisture collection in the under section. I am of the belief that the same holes he drilled for the top freezer and then screened, should be used for the under part...the fridge.
Anyone with knowledge of the basics of dehydrators or with experience regarding making a dehydrator?

 

[Marianne]

I'll side with you on this one. The added air flow will help carry the moisture out, vs slowly baking. JMO, though.

 

[Boogity]

Do you remember the TV commercial where the little boy on the beach tried to suck the last little drop of Soda out of the bottle? He sucked and sucked until he sucked himself into the bottle. I used to use this as a demonstration when I taught engineering at UAB. You cannot remove more air from an enclosed area than air that you allow to enter.

If you have vent holes in the top area of the 'frige they will be useless unless there are matching holes in the bottom area to allow air to flow inward. By allowing outside air to flow inward you may need to add another light bulb or two because the incoming air will act as a cooling agent.

The moisture you found in the bottom of the 'frige may have been due to interior temperatures too low. Condensation. Warm air is capable of holding more moisture than relatively cooler air. If the air temp. in the 'frige is warm enough it will "carry" the moisture from the items inside (vegetables, fruit, meat, etc.) up and out of the vent holes in the top.

Dehydrators are much more sophisticated than a simple box with a heat source inside. Good luck, you'll get it right eventually. These are fun projects to play with.

 

[lwheelr]

Boogity is right.

Vent at the bottom, vent at the top of any of the spaces.

Plus, fan at the bottom, moving the air UP. Heat source at the bottom near the fan.

Vent at the top should be adjustable for best control with various moisture levels in foods.